WASHINGTON -- A key U.S. Senate panel has postponed its vote on a bill that seeks to sanction Russian officials connected to the prison death of Russian lawyer Sergei Magnitsky.

The Senate Foreign Relations Committee was scheduled to vote on June 19 on the "Sergei Magnitsky Rule of Law Accountability Act," before a committee lawmaker requested a last-minute delay.

A committee spokesperson told RFE/RL, "As a result of this request, and consistent with long-standing committee practice regarding holdovers, there will not be a vote on the Magnitsky bill at today's business meeting."

RFE/RL later confirmed that Senator Jim Webb (Democrat-Virginia) had requested the delay. A spokesperson from his office said, "Senator Webb supports the premise of the Magnitsky Act, but has concerns about some of the language in the current draft and has asked that the bill be held over so that he can more closely examine it."

A new date for the vote has not yet been determined.

Passage in the committee was considered the greatest hurdle to the legislation, which calls for visa bans and asset freezes for officials involved in gross human rights violations, but was crafted specifically in response to Magnitsky's 2009 death.

He had implicated top officials in a massive scheme to defraud the Russian government before he was arrested.

His case has become an international symbol of Russia's rule-of-law failings.

A similar bill was approved last week in a U.S. House of Representatives committee.

Russia has warned the U.S. measure could threaten bilateral ties and the administration of President Barack Obama has publicly opposed it.

On June 18, on the eve of the scheduled vote, Obama met President Vladimir Putin for the first time since the Russian leader's reelection.